1. Field of the Present Description
The present invention relates generally to the field of molded parts and relates particularly to compression-molded parts having an embedded conductive layer.
2. Description of Related Art
Compression-molded parts are fabricated using a matched die set consisting of male and female dies. The molding material, which may be a powder, pellets, sheet, a putty-like mass, or a liquid, is introduced into the female die in a partially cured condition and may be preheated prior to being placed in the die. The mold is then closed with the male die member, pressure is applied to force the material into contact with all mold areas, and heat and pressure are maintained until the molding material has cured. The process employs thermosetting resins, and advanced composite thermoplastics may also be compression molded with unidirectional tapes, woven fabrics, randomly orientated fiber mat, or chopped strand. The advantage of compression molding is its ability to mold large, fairly intricate parts with very little labor cost.
Certain compression-molded external fairings and panels on aircraft require lightning strike protection. Prior art methods of providing lighting protection to compression-molded parts include: (1) secondary bonding of a copper mesh to the part via a structural adhesive layer; and (2) painting the compression-molded part with copper-filled paint. A key disadvantage of the secondary bonding process is the added weight of the adhesive. In addition, there is an increase in per-unit cost due to the inherent post-molding processing, the need for additional tooling, and any required rework or repair of surface imperfections. The copper-paint method has a high weight penalty and may provide inconsistent protection due to variations in application thickness. In addition, the copper paint can be easily damaged during routine maintenance and can be inadvertently removed during repair or repaint situations.